Sheet feeding mechanism having a single control member for actuating a suction, air pressure, and pump means



Dec. 27, 1966 A. J. STAINES 3,294,396

SHEET FEEDING MECHANISM HAVING A SINGLE CONTROL MEMBER FOR ACTUATING ASUCTION, AIR PRESSURE, AND PUMP MEANS Filed Nov. 23, 1964 2 Sheets-Sheet1 INVENTOR. v AL RED J. STA/N55 ATTORNEYS Dec. 27, 1966 A. J. STAINES3,294,396

SHEET FEEDING MECHANISM HAVING A SINGLE CONTROL MEMBER FOR ACTUATING ASUCTION. AIR PRESSURE, AND PUMP MEANS Filed Nov. 23, 1964 2 Sheets-Sheet2 INVENTOR. ALFRED J. STA/N55 BY JL'ZZP'MlWZ QM WWW W ATTORNEYS UnitedStates Patent M SHEET FEEDING MECIIAI QISM HAVING A SINGLE CONTROLMEMBER FUR ACTUATING A SUC- TIGN, AIR PRESSURE, AND PUMP MEANS Alfred J.Staines, Shaker Heights, Ohio, assignor to Harris- IntertypeCorporation, Cleveland, Ohio, a corporation of Delaware Filed Nov. 23,1364, Ser. No. 413,100 11 Claims. (Cl. 271-46) The present inventionrelates primarily to a sheet handling apparatus and, particularly, to asheet feeding apparatus having suction separator means for feedingindividual sheets from a pile and an air nozzle means for directing astream of air under the sheet being handled to assist in the separationand feeding thereof.

In the operation of a sheet feeder having suction sheet separator meansand an air nozzle means, it is important to be able to control thepressure of the air flowing through the air nozzle means. Of course, theair pressure should not be on until the suction in the separator meansis on. Moreover, the air pressure is generally controlled or varieddepending upon the stock being fed and the speed of feeding thereof.Without such a control, the sheets in the pile may be disarranged or thesheet being fed may be improperly fed. In particular, it has been foundthat as the speed of the feeding of sheets increases, the air pressureshould increase. Therefore, when the feeder is being jogged or isoperating at low speeds, such as when starting, the air pressure shouldbe low or zero. As the speed of feeding increases, the air pressurelikewise should be increased.

Prior art sheet feeding mechanisms utilize valves in the suction and airpressure lines which are adjustable to vary the suction and air pressuredirected to the separator means and air nozzles. These valves areseparately ad justed and are located at a position remote from theoperators platform at which controls are located for controlling thespeed of operation of the feeding mechanism. Thus, to make the valveadjustments, the operator must leave the operators platform, make theseparate adjustments to the valves in the air and suction lines, andthen return to the operators platform.

Accordingly, a principal object of the present invention is theprovision of a new and an improved sheet feeding mechanism havingsuction separator means and air nozzle means and wherein valves forcontrolling the magnitude of the suction and the air pressure areadjustable by movement of a single control member.

Another principal object of the present invention is the provision of anew and an improved sheet feeding mechanism having suction separatormeans and air nozzle means and wherein valves for controlling themagnitude of the suction and the air pressure are adjustable by movementof a single control member accessible to an operator at the operatorsplatform.

Another important object of the present invention is the provision of anew and an improved sheet feeding mechanism having suction separatormeans and air nozzle means and wherein valves for controlling themagnitude of the suction and the air pressure, as well as the pump meansfor creating the suction and air pressure, are controlled and actuatedby a single movable control member located at the operators platform.

A further object of the present invention is the provision of a new andan improved sheet feeding mechanism having suction separator means andair nozzle means and valves for controlling the magnitude of the suctionand the air pressure and means for adjusting the valves includingseparate cam members for actuating each of the valves and which aremounted for rotation with a shaft member which is rotatable by anoperator on the operators platform.

3,294,396- Patented Dec. 27, 1966 A still further object of the presentinvention is the provision of a new and an improved sheet feedingmechanism having suction separator means and air nozzle means andindividual valves which are cam actuated for con trolling the magnitudeof the suction and the air pressure and wherein each of the valves hasports therein which are in communication with the atmosphere and withthe suction or air pressure line, as the case may be, and wherein theseports provide for breaking the suction in the suction line and for therelease of air pressure, respectively, and each valve includes a membermovable to block communication between the ports and the suction orpressure line, respectively.

Further objects and advantages of the present invention will be apparentto those skilled in the art to which it relates from the followingdetailed description of the preferred embodiment thereof made withreference to the accompanying drawings forming a part of thisspecification and in which:

FIG. 1 is a schematic side elevational view of a mechanism embodying thepersent invention;

FIG. 2 is a schematic view of an enlarged scale of a portion of themechanism shown in FIG. 1;

FIG. 3 is a fragmentary cross-sectional view of the mechanism of FIG. 1,taken approximately on the section line 3-3 of FIG. 1;

FIG. 4 is a cross-sectional view of the mechanism shown in FIG. 2, takenapproximately 0n the section line 44 of FIG. 2;

FIG. 5 is a cross-sectional view of the mechanism shown in FIG. 4, takenapproximately along the section line 55 of FIG. 4;

FIG. 6 is a cross-sectional view of the mechanism shown in FIG. 4, takenapproximately along the section line 66 of FIG. 4;

FIG. 7 is an elevational view of a portion of the mechanism shown inFIG. 3, looking at the mechanism of FIG. 3 as indicated by the line 7-7thereof; and

FIG. 8 is a sectional viewof the mechanism shown in FIG. 3, takenapproximately along the section line 8-3 of FIG. 3.

The present invention provides an improved sheet feeding mechanism forfeeding sheets to a work station and is shown in the drawings aspreferably embodied in a sheet feeding mechanism 10 for feeding sheetsto a printing press 11. The sheet feeding mechanism 10 is of the typewherein the topmost sheet of a pile P is fed into the nip of a pair ofadvancing rolls 13 located forwardly of the pile and which feed thesheet down a feedboard 14 into the printing press 11. The pile isgenerally supported on a suitable hoist which raises the pile as sheetsare fed therefrom, so that the top of the pile is always atsubstantially the same level.

The sheets are fed from the pile P by suitable suction sheet-separatingand feeding means. The suction sheet separating and feeding meansincludes sheet-raising suckers 16 and sheet-forwarding suckers 17. Thesheet-raising suckers 16 engage and grip the rear portion of the topmostsheet in the pile and move vertically to raise it from the next sheet onthe pile and to the forwarding suckers 17. The forwarding suckers 17grip the sheet raised by the suckers 1 6 and move the sheet forwardlytoward the forwarding rolls 13 and move the forward or leading edgethereof into the nip of the rolls 13. The operating mechanism for thesuckers 16 and 17 will not be described in detail since any well-knownoperating mechanism may be utilized, and reference may be made toapplicants copend application, Serial No. 332,596 for a specific showingof a particular type of mechanism for raising and lower-ing the suckers16 and moving the forwarding suckers 17.

The sheet feeding mechanism 10 includes a means for directing a streamof separating air to the edges of the uppermost sheets in the pile to,as is well known, ruflle the edges of the sheets and assist inseparating the topmost sheet from the stack. The means for directing thestream of separating air includes air nozzles 18 located adjacentopposite sides of the pile and positioned to direct the air against therear edges of the uppermost sheets in the pile. The sheet feedingmechanism also includes means for directing a stream of floating orforwarding air between the topmost sheet of the pile and the nextadjacent sheet in the pile toward the forward end thereof to assist inthe separating of the topmost sheet from the pile and to facilitatemoving the sheet forwardly. The floating air functions to provide a filmof air between the topmost sheet and the pile to thereby separate orbreak the forward end of the topmost sheet from the next adjacent sheetso as to facilitate movement of the sheet forward by the forwardingsuckers. The means for directing the floating air toward the forward endof the sheet comprises floating air nozzles 19 located to direct airunder the topmost sheet in the pile and toward the forward end thereof.

The sheet floating air stream, the separating air stream, and thesuction for sucker members 16 and 17 are all controlled by a singlerotary valve 20 which connects the floating air nozzles 19 andseparating air nozzles 18 to an air supply line 21 and which connectsthe sucker members 16 and 17 to a suction supply line 22 in timedrelation with the operation of the sheet feeding mechanism. Theparticular construction of the rotary valve 20 forms no part of thepresent invention and will not be described in detail. It should sufliceto say that the valve does include a valve member which is rotated intimed relation to the movement of the sucker members 16 and 17 and uponrotation, controls the suction in the sucker members and the air flowingthrough the various nozzles describes hereinabove. A particular type ofvalve which might be utilized for this purpose is shown in copendingapplication, Serial No. 290,841, filed June 26, 1963, now Patent No.3,226,107.

The control of the magnitude of the suction and air pressure is quiteimportant in the sheet feeding mechanism. The air pressure should not beapplied to the nozzles 18, 19 until suction of a degree suflicient tohandle the sheets has been applied to the sucker members 16 and 17.Moreover, the air pressure in the nozzles should be such as not todisarrange the sheets in the pile and to provide for effective feedingof the sheets. Generally, the air pressure should be adjusted dependingupon the type of sheet stock being handled and the speed at which thesheets are being fed. The greater the speed of operation, the greaterthe air pressure should be.

Accordingly, the sheet feeding mechanism 10 includes a valve means 24located in the air pressure line 21 and a valve means 26 located in thesuction line 22. The valves 24 and 26 have a common valve body 27 andare operable to control the magnitude of pressure and suction,respectively, in the lines in which they are located. The common valvebody is secured in the frame of the mechanism by suitable screws 28. Thevalve 24 is adjustable in order to vary the air pressure in the line 21.Moreover, in accordance with the present invention, the valves areoperated by an actuating means so as to effect full suction pressure atthe suckers 16 and 17 prior to any pressure being directed through thenozzles 18 and 19, and then increase of the air pressure in the nozzles18, 19 without any increase in the suction applied to the sucker members16 and 17.

The valve 24 for controlling the air pressure in the air supply line 21includes a valve body portion 30 forming a part of the common valve body27. The body portion 30 has an inlet opening 31 and an outlet opening 32which are connected by a bore 33 and through which air pressure in thesupply line 21 is directed. The body portion 30 may have an outletopening 34 communicating with the bore 33 and leading to other mechanismin order to provide air pressure thereto, if desired. Moreover, asuitable air pressure gauge 34a is located adjacent the valve 24 in theair pressure supply line 21.

The body portion 30 of the valve 24 also includes a plurality of ports35 communicating with the atmosphere. The ports 35 also communicate withthe bore 33 by a passageway 36 extending therebetween. As viewed in thedrawings, the passageway 36 is blocked by a movable member 37 comprisinga spherical ball member. The ball member 37 is movable from the positionshown in FIG. 6 wherein it engages a seat 38 and blocks any flow offluid through the passageway 36 to the ports 35 to a position out ofengagement with the seat 38 at which air may flow through the passageway36 through the vent ports 35.

The ball member 37 is biased by a spring 40 downwardly, as viewed inFIG. 6, into engagement with the valve seat 38 and, thus, is biased to aposition wherein the ports 35 are blocked from communication with thebore 33. It can be seen, of course, that when the ball 37 is in positionblocking communication between the ports 35 and the bore 33, airpressure flows through the valve inlet and outlet ports to the valve 20which controls the flow of air to the air nozzles 18, 19. Air pressurein the bore 33 acts on one side of the ball 37 and if sufficient toovercome the force of the spring 40, will move the ball 37 away from theseat 38 and, thereby, provide a leak of air pressure to the atmospherethrough ports 35. Thus, the air pressure in the line 21 is reduced. Ofcourse, if the bias of the spring 40 is greater than the air pressure,the ball 37 remains in engagement with the seat 38 and prevents leakageof air to the atmosphere and, therefore, provides maximum air pressurein the valve.

The air pressure in the air line 21 and nozzles 18, 19, as should beapparent from the above, is a function of the bias on the spring 40 andas the bias on the spring 40 increases, the air pressure in the air linelikewise increases. The bias on the spring 40 may be increased bymovement of a plunger member 41 vertically in a bore 42 in the valvebody portion 30. The plunger member 41 has a passageway or opening 43therein in which one end portion of the spring 40 is positioned. Theother end of the spring 40, of course, engages the surface of the ballmember 37. The plunger member 41 is movable in a vertical direction inthe bore 42 by means of a cam member 45 which engages the upper surface41a of the plunger member 41 and the plunger member 41 is held inengagement with the surface of the cam 45 by the spring 40.

In the position shown in FIG. 6, the plunger 41 is in its uppermostposition and the bias on the spring 40 is at its lowest. In thisposition, air pressure directed into the bore 33 causes the ball 37 tomove away from the seat 38 and causes leakage of the air pressure to theatmosphere and provides zero air pressure in the valve 20. Upon movementof the cam 45 in a clockwise direction from the position shown in FIG. 6for approximately degrees, no increase in the compression of the spring40 is effected because the cam surface portion 46 which will haveengaged the upper surface 41a of the plunger member 41 is a dwellsurface. Further movement, however, of the cam member 45 will effect alowering of the plunger member 41 causing compression of spring 40 andan increase in the biasing force of the spring 40 tending to hold theball 37 in engagement with the seat 38. This causes a reduction in theleakage of air past the ball 37 and an increase in the air pressure inthe bore 33 and valve 20. As the came member 45 is rotated, the amountof biasing force on the spring 40 is increased progressively so as todecrease the air leaking past the ball member 37 to the ports 35 leadingto the atmosphere, thus progressively increasing the pressure in thebore 33 and, in turn, increasing the pressure in the valve 20 andnozzles 18, 19.

The valve member 26 which is located in the suction line 22 is operableto control the amount of suction in the suckers 16 and 17. The valvemember 26 includes a valve body portion 50 forming a part of the commonvalve body 27 and having a suction inlet port 51 and a suction outletport 52 which are in communication with each other through a chamber 53.A suitable passageway 54 also communicates with the chamber 53 and intowhich a relief valve member 55 may be positioned. The relief valve 55 isadjustable to determine the maximum suction pressure in the suctionline. The valve 55 functions as a safeguard to prevent too great asuction build-up in the suction line. This valve is adjusted dependingupon the pump and particular structure of the feeding mechanism 18. Thevalve body portion 50 also has an opening 54a in communication with thechamber 53 and which leads to a gauge 54b. The body portion 50 of thevalve 26 also includes a plurality of ports 56 in communication with theatmosphere. The ports 56 also communicate with the chamber 53 andprovide a release for the suction in the chamber 53 when incommunication therewith.

The valve 26 further includes a means for blocking off the ports 56 fromthe chamber 53. This means comprises a plunger member 58 which ismovable vertically, as viewed in FIG. 5, in a bore 59 in the valve bodyportion 50. The plunger 58 has a suitable opening 60 in the bottomportion thereof, as viewed in FIG. 5, into which one end of a coilspring 61 is positioned, the other end of the coil spring bears againsta spring seat 62 formed on the valve body portion 58. The plunger member58 is moved in the bore 59 by means of a cam member 61. The cam 61 uponmovement in a clockwise direction causes vertical lowering movement ofthe plunger 58 from the position in which it is shown in FIG. 5. Uponinitial movement of the cam 61 in a clockwise direction, as viewed inFIG. 5, the surface portion 62 thereof engages the upper surface portion58a of the plunger 58 and causes the plunger 58 to be moved verticallydownwardly. As the plunger 58 moves downwardly, a portion 58b thereofmoves to block ports 56 from chamber 53 and the amount of communicationbetween the chamber 53 and the vent ports 56 is reduced. After the cam61 is moved through approximately 90 degrees of rotation, the ports 56are completely blocked from chamber 53 thereby providing maximum suctionin the chamber 53 which, in turn, provides maximum suction in the suckermembers 16 and 17. Further rotational movement of the cam 61 does notchange the suction pressure in the chamber 53 for a dwell portion 62a ofthe cam engages the plunger 58. The dwell portion of the cam member 61is provided with a plurality of indentations 64 which cooperate withsurface 58a of the plunger 58 and tend to hold the cam 61 in theposition to which it is rotated. The rotation of the cam 61 in theclockwise direction is limited by a stop means. The stop means comprisesa pin 65 which projects outwardly of the cam 61 and engages a portion 66of the body portion 50 when rotated to its limit in the clockwisedirection.

The cam members 45, 61 for actuating the valves 24, 26

are part of a manually actuated operating means for operating thesevalves. The cams 45 and 61 are mounted on a common control shaft 70. Thecontrol shaft 70 is rotatably supported by the common valve body at oneend thereof and in the frame of the feeding mechanism. The cams 45 and61 are fixedly secured to shaft 70 and positioned on the shaft 70 sothat when the cam 45 is in the position shown in FIG. 6, the cam 61 isin the position shown in FIG. 5. Thus, in this position of the earns,the air and suction pressures are at a minimum and preferably zero.

The shaft 70 extends transverse to the direction of movement of thesheets and to a position adjacent an operator's platform 75 which ispositioned between the printing press 11 and the pile of sheets P. Theshaft 70 has a control knob 76 fixedly secured on the end thereofadjacent to the platform 75 and which is readily accessible to anoperator standing on the platform 75. An operator standing on theplatform 75 therefore may rotate the knob 76 and, in turn, rotate theshaft 70 to control the air pressure and suction pressure. The controlsfor operating the printing press 11 and the feeder mechanism andto-control the speed thereof are also located so as to be accessible tothe operator standing on the platform 75. Thus, an operator standing onthe operators platform need not move from the platform 75 in order toadjust the air pressure in the nozzles 18, 19 when the speed of thepress is varied.

The air pressure and the suction applied to the valves 24, 26 is createdby a suitable pump means shown schematically in FIG. 1 and designated80. The pump means 80 may comprise any suitable single type of pumpmechanism for providing air and suction in the air and suction lines 21and 22, respectively, or may comprise separate pumps. The pump means 80is shown as a single pump mechanism actuated to provide the suction andair pressure upon initial rotation of the shaft 70 from the positionshown in the drawings. To this end, the shaft 70 carries a trip member81. The trip member 81 comprises a cam or collar member rigidly securedto the shaft 70 for rotation therewith and has flats 82 and 83 spacedtherealong. The trip member 81 cooperates with a pair of switch members84, mounted in the frame of the machine adjacent thereto to effectactuation of the 'pump means 80.

The switch means 84 is a normally open switch having a control member 86which engages the periphery of the cam or trip member 81 and is actuatedthereby. The switch 85 is a normally closed switch having a controlmember 87 which engages the periphery of the trip member 81 and iscontrolled thereby. The trip member 81 and the switches 84, 85 are shownin FIG. 8 in the position in which they occupy when the shaft 70 and thecams 61 and 45 are in the position wherein minimum air and suctionpressures are in the air and suction lines, respectively. In thisposition, the control member 86 of the normally open switch 84 is inengagement with the flat 82 on the periphery of the trip member 81. Inthis position, the switch 84 is in its normal position with its switchcontacts open. The switch 85, however, is held out of its normalposition by engagement of its control member 87 with the circularperiphery of the trip member 81 and, thus, is open also.

When it is desired to apply suction and air pressure in the supplylines, the shaft 70 is rotated in a clockwise direction. Initialrotation of the trip member 81 clockwise, from the position shown inFIG. 8, causes the control member 86 for the switch 84 to ride off thefiat 82 and into engagement with the periphery of the cam member 81.This moves the control member 86 thereof to the right, as shown in FIG.8, causing the contacts of the switch 84 to be closed. At substantiallythe same time, the control member 87 for the switch 85 moves intoengagement with the flat 83 causing its switch contacts to take theirnormal position, namely, closed. In this position, with both switchesclosed, a circuit is completed through the contacts of the switcheswhich are in series to a relay which establishes a holding circuitaround the contacts of the switch 85 and, at the same time, energizescontacts in the circuit for the motor controlling the pump means 80.Further movement of the trip means in the clockwise direction causes thecontrol member 87 for the switch 85 to ride off flat 83 and onto theperiphery of the trip member. This causes the control member 87 to moveto the right and opens contacts of the switch 85. The above-noted relay,however, remains energized, even though the switch 85 is returned to itsopen position, due to the holding circuit around the contacts of theswitch 85.

When it is desired to decrease the air pressure in the nozzles 18, 19,the shaft 78 is turned in a counterclockwise direction. Upon rotation ofthe shaft 70 in a counterclockwise direction, toward the position shownin FIG. 8, initially the circuit remains in a condition wherein thecontacts of the switch 84 are closed, while the contacts of the switch85 are open. However, the flat 83 permits the control member 87 of theswitch 85 to move outwardly causing closing of the contacts thereof.This performs no function at this time since a circuit is stillmaintained through switch 84 and the holding contacts around thecontacts for the switch 85. The flat 82 then comes into engagement withthe control member 86 of the switch 84 causing the control member 86 tomove to the left, as viewed in FIG. 8, causing the contacts of theswitch 84 to open. This breaks the circuit to the relay which opens thecontacts connected with the pump motor and the contacts of the holdingcircuit, thereby deenergizing the pump motor. The control circuitincluding the switches 84, 85 thus functions to prevent operation of thepump after a power cutoff, without returning the trip member 81 andswitches to the condition that they have when in the position shown inFIG. 7.

As best seen in FIG. 7, the sheet feeding mechanism includes anindicator 90 secured to the shaft 70 for movement therewith and anindicator plate 91 secured to the frame of the machine. The indicatorplate has a zero or off position in which it is located in FIG. 8. Asthe shaft 70 is rotated to turn on the pump means 80 and increase thesuction, the indicator 90 moves to indicate suction increase on theplate 91. The plate 91 includes a plurality of numbers indicatingdifferent air pressures in the nozzles 18, 19 and when the indicatorpoints to a particular number, a corresponding pressureis applied to thenozzles 18, 19.

From the above description, the operation of the preferred embodiment ofthe present invention should be apparent. With the structure in theposition wherein the cams 45 and 61 are in the position shown in FIGS.and 6, and the switches 84 and 85 are in the position shown in FIG. 8,the indicator 90 is in a position, shown in FIG. 7, wherein it indicatesthat the vacuum pressure is zero and the air pressure is zero. Rotationof the shaft 70 in a clockwise direction, as viewed in FIGS. 7 and 8,does not affect the air pressure due to the fact that the cam dwellsurface portion 46 of the cam 45 will be running in engagement withplunger surface 41a of the valve 24. However, the suction is increaseddue to the fact that the portion 62 of increasing radius of the cam 61forces the plunger 58 downwardly in the bore 59 of the valve 26. Oncethe vacuum is fully on, the air pressure is then progressively increasedupon further rotation of the shaft 70 and may be incrementally increasednine steps, as indicated on the indicator plate 91, which cooperateswith the indicator arrow 90. The pressure is increased due to the factthat the portion of increasing radius of the cam 45 now runs inengagement with the plunger 41 of the valve 24 and forces the plunger 41of the valve 24 downwardly to increase the bias of the spring 40. Uponreverse rotation of the shaft 70 initially, of course, the pressure inthe air line 21 is decreased to a point where it is reduced to aminimum, and then the pressure in the suction nozzles is decreased tothe point where it is entirely off, and the cam members have beenreturned to the position shown in FIGS. 5 and 6, at which time theswitches 84 and 85 are operated to de-energize the pump means 80.

From the above description, it should be apparent that applicant hasprovided a new and improved mechanism and that certain modifications,changes, and adaptations may be made therein by those skilled in the artto which it relates, and it is intended hereby to cover all suchmodifications, changes, and adaptations which fall within the scope ofthe appended claims.

What I claim is:

1. A sheet feeding mechanism for feeding sheet material from a pilecomprising suction feed means for engaging the top sheet of the pile andfeeding it forwardly thereof, nozzle means for directing a stream of airtoward said sheet to assist in the feeding thereof, suction and airpressure supply lines leading from a source of suction and air pressurerespectively to said suction feed means and said nozzle meansrespectively, first valve means in said suction supply line operable tocontrol the pressure in said suction supply line, second valve means insaid air supply line operable to vary the pressure in said air supplyline, and actuating means for said first and second valve meanseffective to operate said first valve means to provide a predeterminedsuction pressure in said suction supply line and then subsequentlyoperate said second valve means to apply air pressure to said air supplyline of a progressively increasing magnitude including a single controlmember for operating said actuating means.

2. A sheet feeding mechanism for feeding sheet material from a pile to asheet handling machine comprising suction sheet separating means forenergizing the top sheet of the pile and feeding said sheet forwardlythereof, nozzle means for directing a stream of air toward said sheet toassist in the feeding thereof, suction and pressure supply lines leadingfrom a source of suction and air pressure respectively to said suctionfeed means and said nozzle means respectively, an operators plat formadjacent said sheet handling machine and remote from said sheetseparating means and on which the operator may stand and control thespeed of operation of said separating means, first valve means in saidsuction supply line operable to control the pressure in the suctionsupply line, second valve means in the air supply line operable to varythe pressure in said air supply line, and actuating means for said firstand second valve means effective to operate said first valve means toprovide a predetermined suction in said supply line and thensubsequently operate said second valve means to apply air pressure tosaid air supply line of a progressively increasing magnitude andincluding a single control member for operating said actuating means andaccessible to an operator standing on said operators platform.

3. A sheet feeding mechanism for feeding sheet material from a pile to asheet handling machine comprising suction sheet separating means forengaging the topmost sheet of the pile and feeding it forwardly thereof,nozzle means for directing a stream of air toward the sheet being fed toassist in the feeding thereof, pump means for creating a suctionpressure and an air pressure, suction and pressure supply linesconnected with said pump means for delivering suction and air pressurerespectively to said suction sheet separating means and said nozzlemeans, an operators platform adjacent to said sheet handling machine andremote from said sheet separating means and from which an operator maycontrol operation of said separating means, first valve means in thesuction supply line operable to control the pressure in the suctionsupply line, second valve means in the air supply line operable tocontrol the pressure in said air supply line, and actuating means forsaid first and second valve means elfective to operate said first valvemeans to provide a predetermined suction in said suction supply line andthen operate said second valve means to apply air pressure to said airsupply line of a progressively increasing magnitude and including asingle control member movable to operate said actuating means andaccessible to an operator on said platform, and means for energizingsaid pump means in response to initial movement of said control member.

4. A sheet feeding mechanism for feeding sheet material from a pilecomprising suction feed means for engaging the topmost sheet of the pileand feeding it forwardly thereof, nozzle means for directing the streamof air toward the sheet being fed to assist in the feeding thereof, pumpmeans forcreating a suction pressure and an air pressure, suction andpressure supply lines connected with said pump means for deliveringsuction and air pressure respectively to said suction feed means andsaid nozzle means, first valve means in the suction supply line operableto control the pressure in the suction supply line, second valve meansin the air supply line operable to control the pressure in said airsupply line, and actuating means for said first and second valve meanseffective to operate said first valve means to provide substantialsuction in said suction supply line and then operate said second valvemeans to apply air pressure to said air supply line of a progressivelyincreasing magnitude and including a single control member movable tooperate said actuating means, and means for energizing said pump meansin response to initial movement of said control member.

5. A sheet feeding mechanism for feeding sheet material from a pilecomprisinr suction feed means for engaging the top sheet of the pile andfeeding it forwardly thereof, nozzle means for directing a stream of airtoward said sheet to assist in the feeding thereof, suction and airpressure supply lines leading from a source of suction and air pressure,respectively, to said suction feed means and said nozzle meansrespectively, first valve means in said suction supply line operable tovary the pressure therein, second valve means in said air supply lineoperable to vary the air pressure therein, said first and second valvemeans each including a control member movable to control the pressure intheir respective lines, first and second cam members associated witheach of said first and second valve means and-operatively connected withsaid control members respectively and operable upon movement to effectmovement of said control members, and a shaft member carrying said firstand second cam members and rotatable to effect rotation of said firstand second cam members to move said control members of said first andsecond valve means, said first cam member having a cam surface operableto move said control member of said first valve to establish a suctionof a predetermined degree in said suction feed means, and said secondcam member having a cam surface operable to move said control member forsaid second valve to establish an air pressure in said nozzle meansafter suction is established in said suction feed means and with the airpressure progressively increasing upon continued movement of saidcontrol member.

6 A sheet feeding mechanism as defined in claim wherein said first cammember has an actuating surface portion for effecting movement of thecontrol member for said first valve means to increase suction in saidsuction line and a dwell surface portion, and said second cam member hasa dwell portion for engaging the control member for said second valvemeans while said actuating sur-. face portion of said first cam memberengages the control member for said first valve means and an actuatingportion for engaging the control member for said second valve meanswhile said dwell portion of said first cam member engages the controlmember of said first valve means. I

7. A sheet feeding mechanism as defined in claim 5 wherein said firstvalve means comprises a valve body having suction inlet and suctionoutlet ports and at least one vent opening to the atmosphere andcommunicating with said suction inlet and outlet ports, said controlmember for said first valve means comprising a plunger means movable bysaid first cam member to block communication of said inlet and outletports with said vent port, and spring means applying a biasing forceagainst said plunger means to hold said plunger means in engagement withsaid first cam member.

8. A sheet feeding mechanism as defined in claim 5 wherein said secondvalve means comprises a valve body having inlet and outlet ports and atleast one vent port communicating With the atmosphere and with saidinlet and outlet ports, said control member for said second valve meanscomprising a plunger member, a movable member for at least partiallyblocking communication between said inlet and outlet ports and said ventport, spring means acting between said plunger member and said movablemember and biasing said plunger member into en- 10 gagement with saidsecond cam member and said movable member into a position blockingcommunication between said inlet and outlet ports and said one ventport.

9. A sheet feeding mechanism for feeding sheet material from a pilecomprising suction feed means for engaging the top sheet of the pile andfeeding it forwardly thereof, nozzle means for directing a stream of airtoward said sheet to assist in the feeding thereof, suction and airpressure supply lines leading from a source of suction and 'airpressure, respectively to said suction feed means and said nozzle meansrespectively, first valve means in said suction supply line operable tovary the pressure therein, second valve means in said air supply lineoperable to vary the air pressure therein, said first and second valvemeans each including a control member movable to control the pressure insaid respective lines, first and second cam members associated with eachof said first and second valve means and operatively connected with saidcontrol members respectively and operable upon movement to effectmovement of said control members, a shaft member carrying said first andsecond cam members and rotatable to effect rotation of said first andsecond cam members to move the control members of said first and secondvalve means, pump means for creating said suction and air pressure, andmeans for energizing said pump means in response to rotation of saidshaft member.

in). A sheet feeding mechanism as defined in claim 9 further includingswitch means actuatable to energize operation of said pump means andtrip means carried by said shaft member and operable to energize saidswitch means to effect operation of said pump means upon initialrotation of said shaft member.

11. A sheet feeding mechanism for feeding sheet material from a pilecomprising suction feed means for engaging the top sheet of the pile andfeeding it forwardly thereof, nozzle means for directing a stream of airtoward said sheet to assist in the feeding thereof, suction and airpressure supply lines leading from a source of suction and air pressure,respectively, to said suction feed means and said nozzle means,respectively, first valve means in said suction supply line operable tovary the air pressure therein, second valve means in said air supplyline operable to vary the air pressure therein, said first and secondvalve means each including a control member movable to control thepressure in said respective lines, first and second actuating membersassociated with each of said first and second valve means andoperatively connected with said control members respectively andoperable upon movement to effect movement of said control members, saidfirst actuating member being operable to move said control member ofsaid first valve to establish a suction of a predetermined degree insaid suction feed means, said second actuating member being operable tomove said control member of said second valve to establish an airpressure in said nozzle means after suction is established in saidsuction feed means and with the air pressure progressively increasingupon continued movement of said control member by said actuating member,and a movable member carrying said first and second actuating membersand movable to effect movement of said first and second actuatingmembers to effect movement of said control members of said first andsecond valve means.

References Cited by the Examiner UNITED STATES PATENTS 1,587,816 6/1926Broadmeyer 27127 1,716,948 6/ 1929 Broadmeyer 27127 2,046,728 7/ 1936Dawson 27127 X 2,764,407 9/ 1956 Alix 271-26 2,874,962 2/1959 Layden27127 2,973,610 3/1961 Randall 271-27 X M. HENSON WOOD, JR., PrimaryExaminer.

V. C. WILKS, Assistant Examiner.

1. A SHEET FEEDING MECHANISM FOR FEEDING SHEET MATERAIL FROM A PILECOMPRISING SUCTION FEED MEANS FOR ENGAGING THE TOP SHEET OF THE PILE ANDFEEDING IT FORWARDLY THEREOF, NOZZLE MEANS FOR DIRECTING A STREAM OF AIRTOWARD SAID SHEET TO ASSIST IN THE FEEDING THEREOF, SUCTION AND AIRPRESSURE SUPPLY LINES LEADING FROM A SOURCE OF SUCTION AND AIR PRESSURERESPECTIVELY TO SAID SUCTION FEED MEANS AND SAID NOZZLE MEANSRESPECTIVELY, FIRST VALVE MEANS IN SAID SUCTION SUPPLY LINE OPERABLE TOCONTROL THE PRESSURE IN SAID SUCTION SUPPLY LINE, SECOND VALVE MEANS INSAID AIR SUPPLY LINE OPERABLE TO VARY THE PRESSURE IN SAID AIR SUPPLYLINE, AND ACTUATING MEANS FOR SAID FIRST SAID SECOND VALVE MEANSEFFECTIVE TO OPERABLE SAID FIRST VALVE MEANS TO PROVIDE A PREDETERMINEDSUCTION PRESSURE IN